Inspecting wire drawing die



Feb. 10, 1948.

R. H. SAVIERS INSPECTING WIRE DRAWING DIE Filed Sept. 15, 1944 [mm afar:F0556? Have) 54mm,

i atenterl Feb. l0, 194$ INSPECTING WIRE DRAWING me Robert HenrySaviers, Morrisville, Pa.,assignor to The American Steel and WireCompany of New I Jersey, a corporation of New Jersey 7 ApplicationSeptember 15, 1944, Serial No. 554,304

2 Claims. (01. 18-55) This invention is concerned with inspecting wiredrawing dies to determine. whether their various parts are properlymade.

A specific example of the invention is illustrated by the accompanyingdrawings, in which:

- Figure 1 is a vertical section of apparatus suitable for carrying outthe invention;

Figure 2 is a longitudinal section of a die; and Figure, 3 is a detailinvolved in inspecting the die of Figure 2.

' More specifically, these drawings illustrate a tungsten carbide diehaving'the usual steel shell I, with a ground and polished cylindricaloutside, mounting the tungsten carbide insert 2 in which thedie hole isformed to provide the bell section 3, the smoothing out section 4, theconstricted bearing section 5 and the countersunk section 6, with theends I and 8 of the steel shell I ground and polished to form rightangular planes respecting the cylindrical outside of the steel shell Iand the axis of the die hole, and with the die hole axis concentric withthe axis of this cylindrical outside. These various parts bear theserelative relations, and the various sections have predetermined shapesand a proper finish, in the case of a properly made die, and deviations,characterizing an improperly made die, cause wire drawing trouble.Therefore, it is desirable to inspect such wire drawing dies todetermine whether they are properly made. I

. According to the present invention, a metal cylinder 9 is providedwith an internal bore III that is ground and polished to fit the outsideof thesteel shell I, of the die, as closely as is possible whilepermitting the die to slide in the bore. This cylinder 9 is then set onend, on the ram ll of a vertically acting press, with the bottom end ofthe bore l0 closed by a cylindrical metal plug l2 having at least itstop surface ground and finished as truly as possible at right angles toits side and with the latter ground and polished to fit the inside ofthe bore it! as does the steel shell I of .the die. Thermoplasticmaterial [3 is then placed in the bore ill on top of the plug [2, aseparator I4 is stufied into the bearing section of the wire drawingdie, with this separator made of material inert to the thermoplasticmaterial l3, the die is then slid into the bore ID, on top of thisthermoplastic material l3, more of this material is placed on top of thedie, inside the bore 10, and a cylindrical metal piston l5,

having its side ground and finished to fit the bore ill, in the samefashion as described in connection with the plug l2 and the die, andwith at least its bottom surface ground and finished in the same manneras the topof the plug I2, is then slid in the bore with thisbottomsuriace on the material. The thermoplastic material l3 may be oneof the synthetic resin products, commonly used for the purpose ofmounting metal specimens for microscopic examination, which are providedthe art in the form of a powder which becomes plastic when properlyheated. The resin product may be either of the type which is permanentlythermoplastic or which becomes infusible,aiter heating and compression,and is preferably opaque. Furthermore, the press, providing theram ll,may be a specimen mounting press of the type commercially available formounting metal specimens in such plastic material for microscopicexamination.

Continuing, heat is next applied the thermoplastic material l3, as bymeans of a heater l6 encircling the outside of the cylinder 9, andpressure is applied to the thermoplastic material on both sides of thedie and directed toward the die, as by operation of the ram If so thatit raises until the top of the piston l5 contacts an immovable crosshead11, force being applied'to the ram H in any fashion. The pressureapplied to the material l3, on opposite sides of the die, should besufficient so that as the material becomes plastic, due to its heatingby the heater [6, it is forced against both ends of the die and into thedie hole thereof under adequately heavy pressure to assure completecontact of the material with all parts of the die which it can possiblycontact. The manufacturers of synthetic resin thermoplastic productsprovide instructions as to the temperature and pressure their userequires, and these instructions may be followed in determining theproper temperature and pressure required to mold the plastic massesfirmly against both ends of the die and into its die hole.

After properly carrying out the above phase, the pressure is released bylowering the ram H and the material is cooled as by turning off theheater 16. After cooling, the piston I5 is withdrawn from the cylinder 9and the molded plastic impressions, resulting from the describedprocedure, are removed from the cylinder 9. These molded impressionswill be found to be stuck to both sides of the die, and by pullinggently on them they can be separately removed axially of the die holedue to the separator l4 separating the impressions at the die holebearing section. Incidentally, this separator may be satisfactorily madefrom cotton since this has been found to be non-reactive to mostsynthetic resin thermoplastic materials.

Now, since the side of the plug l2, the outside of the steel shell I, ofthe die, and the piston [5 all formed precision fits with the bore I ll,and since the top of the plug l2 and the bottom of the piston I5 were,within precision limits, at true right angles to the various cylindricalparts, the separated impressions may he set on the flat mounting stageof api'ojectioii microscope and examined for any deviations from thatrelationship of the parts which should prevail if the die is properlymade. Thus, in the case of the illustrated impression, the bottom-; l 8represents a flat surface that is at right angles to the cy lindricaloutside of the steeljlieli -l 'Tlie opposite surface I 9 of thisimpression is ,plajllel to the surface [8 only in case the end "I "ofthe steel shell of the die was at xielitsanglesetqthe shells cylindricaloutside. The die-hole portion of the impression provides a means fordetermining whether the die hole is axially concentric with thecylindrical outside of the -steel shell I, this", being do'iie b 'ii'ieau'rin'g whether the axis of the die hole impre n is at right'a'ngles tothe bottomfo'f the ifn" ss'io'ii and by rotation of the impressionto'determ'ine 6fist.- Finally, the i hole port on 01' the impress onprovides a means for measuring the diameters and angularities'of th(rariti s dle hole secti ns, since the part 2( l fof th ejfimpres'siohwas 'ii'iolded by the el p t is e. whit ewes por 21 was m uedbythfesmofothifig'out section 4, While the fragmentary nib 1 22 was moldedbythe bearer yibus y explained, it is coniiei fecti nst e rest 0 n: of aprojectio Q cro'sco n a ed i hllfii ?bififiBPW i o a screen dir ei iv 'than m as rem s a Although the for o 5 explains the mode ofinspectin'g'ithe fet" en {of the die,-it is obi js t t th Pres i ;ie rm. h exitehd or the die'proyihes a-ineans idr'mspectme that end.

;I claim:

wire dr'awin 1. 'A metho ti install-lg the we we re v efsaid'die liaving'a sheli withfa cylindrical outer I surge; e, "the 'fs hell mounting fani e in wlv ie ttlieidi ho i orm d concentric with'the ut'er -surtae for,h shelhthe die hole having afc'onjstric Q Q P e dst e the mold at bothends of the die in amounts more than sui'licient to fill the respectiveends of the tic impressions when solidified axially from the hmpres'sion'hy means 0 De of the typeeasting an die hole 2. A method 'ofinspecting the die hole of a.

wire drawing die said die having a shell with a ylind-ri'cai outersurface, the shell mounting an insert in which the die hole is formedcongentricwith the outer surface of the shell, the die hole having aconstricted bearing section inwardly of the ends thereof, said methodcomprising inserting a separator to which thermoplastic resin .isiionereactive completely across the die 'h'ole constricted bearingsection, placing the die in a mold h'a-vingh cylindrical bore closelyfittng the outer cylindrical surface of the shell, the die fbingtplace'din the mold intermediate the ends of such mold, vinserting thermoplasticresin in the mold at both ends 'of the die in amounts morethanasuflicient "to fill the respective ends of the die-"hole, applyingpressure and heat to such resin by means of surfaces at right angles tothe bore-of the mold to force the resin against the die ends "and :intothe idle hole, to make an impression 'of the die hole that is separableinto two parts for removaLhecause "of said separat ing material,releas'ing such pressure, removing the die from the mold, and removingthe two plastic impressions "when solidified axially from the die'hole,the 'q'uantity of resin introdu'ced into the'r'n'oldion each'slde of thedie being suflicient to"formpedestals on the ends of the plasticimpressionsof the die hole.

ROBERT HENRY SAVIERS.

7 REFERENCES CITED I, The refer'r'ices are of record in the file of this"patent:

UNITED STATES PATENTS

